Centrifugal mold end closure means



Sept. 26, 1961 J. H. BEYER 3,001,253

CENTRIFUGAL MOLD END CLOSURE MEANS Filed Sept. 29, 1959 IN VEN TOR. Jaw-m H Bzvse 3 001,253 CEUGAL MOE!) END CLOSURE MEANS John H. Beyer, Beverly, N.J., assignor to United States Pipe and Foundry Company, Birmingham, Ala., a corporation of New Jersey Filed Sept. 29, 1959, Ser. No. 844,604 4 Claims. (Cl. 22-65) This invention relates to improvements in apparatus for centrifugal casting of bell and spigot pipe in horizontal metal molds, and more specifically is related to a removable spigot end closure or dam means.

In the centrifugal casting of pipe in horizontal metal molds by the method disclosed in Patent No. 2,853,755, the molten metal is poured into the spinning mold through the bell end of the mold by means of a horngate where it becomes distributed evenly along the length of the mold. In order to prevent the metal from pouring out of the spigot end of the mold, an end dam must be provided. In previously used processes, the end dam consisted of a fixed ring mounted at the spigot end so as to provide an inwardly extending flange which prevented the flow of molten metal out the spigot end of the mold. In these prior processes the pipe was extracted by means inserted into the bell end of the pipe so that the fixed end dam did not interfere with the extraction. However, in the process of the above named patent, the pipe is extracted by means of a push out lance which enters into the spigot end of the mold and pushes against the end of the pipe. With this method of extraction the fixed end dam cannot be used since it will prevent the pushout lance from entering the mold and engaging the end of the pipe. Thus it is necessary to provide a spigot end dam or closure means which is not fixed in place and which may be moved clear of the end of the mold to permit extraction and moved back into position to close oif the spigot end of the mold during casting. :In order that the casting machine may attain maximum casting efficiency, the end dam should be capable of being moved into place easily and rapidly without placing any additional burden on the operator or slowing down the cycle. Accordingly, the object of this invention is the provision of a means for closing off the spigot end of the mold during casting without interfering with the extraction operations.

A further object of this invention is the provision of a spigot end dam which may be moved easily and quickly into place during casting and moved clear of the mold during extraction.

Specifically, the object of this invention is the provision of a spigot end dam mounted on a pivotable arm for swinging the end dam from a position adjacent the end of the mold to a position clear of the end of the mold.

More specifically, the object of this invention is the pro vision of a spigot end dam mounted on a pivotable arm which is also movable normal to the pivoting plane.

Further objects and advantages will be apparent from a consideration of the description taken in view of the drawings in which:

FIGURE 1 is a side elevation View of a casting machine equipped with the spigot end closure mechanism of this invention.

FIGURE 2 is a side elevation view of the spigot end.

portion of the casting machine showing the spigot end dam withdrawn from the mold.

FIGURE 3 is an enlarged cut away View of the spigot end of the casting machine of FIGURES 1 and 2 showing the spigot end dam in detail.

FIGURE 4 is the same view as FIGURE 3 showing spigot end dam of different construction.

Casting machines with which the instant invention may be utilized, of which FIGURE 1 is an example, consist of a horizontal bed 1 of conventional design provided Patented Sept. 26, 1961 with rails 2 on which carriage 3 is adapted for reciprocal movement by hydraulic cylinder 4 carriage. A cylindrical metal mold 5 is rotatably mounted in carriage 3 by means of rollers not shown. Power for rotation of the mold is supplied by electric motor 6 mounted on the carriage and is supplied to the mold through a suitable drive mechanism such as gears 7. Cooling of the mold 5 is effected by spraying a cooling fluid upon its exterior by means of a plurality of spray nozzles, not shown, in a conventional manner.

Molten metal is poured through the bell end core 8 into the rotating mold 5 from pouring ladle 9 and is guided into the mold by horngate 10, the small end of which extends through the bell core into the interior of mold 5. At the end of the bed 1 opposite the pouring end, there is provided a fixed support 11 on which is mounted combination pushout and spray coating lance 12. The free end of the lance is provided with a pushout ring or head 13 which is smaller than the inside diameter of the mold but larger than the inside diameter of the pipe being cast, and the spray coating means, not shown, is retractably mounted inside the lance 12;

The spigot end closing means of the instant invention is shown in position at the spigot end of mold 5. On one side of water box or carriage 3 is mounted air cylinder 14 which is coupled to shaft 15 extending through sleeve 16. The sleeve 16 is in alignment with air cylinder 14 and is axially spaced therefrom to permit the air cylinder to make a complete stroke. The shaft 15 is provided with a'pin 17 that protrudes into slot 18 provided in sleeve 16. Alternatively, the slot could be cut in shaft 15 and the pin 17 could be affixed to sleeve 16. The slot 18 extends generally axially, but at the end remote from the air cylinder 14 it follows a helical path for about onefourth the circumference of the sleeve. On the end of the shaft 15 opposite the air cylinder, there is mounted lever arm 19 having a cage 20 mounted at its free end in which end dam 21 is rotatably mounted. FIGURE 2 shows the end darn rotated out of the path of the mold.

FIGURES 3 and 4 show structures which are satisfactory for holding the end dam in position so that it may rotate with mold 1. In the embodiment shown in FIGURE 4, the end dam is mounted on a shaft 24 which passes through bearing means 22. The bearing means may consist of ball bearings as shown or any other suitable bearing means such as roller hearings or bushing, and it is flexibly mounted in cage 20 by means of studs 23 passing through silicon rubber mounts 25. In the embodiment shown in FIGURE 3, the end dam 21 is loosely mounted on shaft 24 which is securely mounted to cage 20. The end of the shaft is flared so that the end dam will not come ofi during operation. The end dam when positioned in the spigot end of the mold rides against bearing plate 26 which is flexibly mounted by means of studs 27 which pass through coil springs and cage 20. The above embodiments are merely illustrative of many ways in which the end dam 21 may be rotatably mounted on the end of lever 19 and are not to be taken as limiting on the scope of the invention. Also, while each of the specific illustrations uses a flexible mounting between the end dam 21 and the cage, this feature is provided to accornmodate small mis-alignments of the end dam with the mold or any eccentricity in the mold or end dam and is not essential to the operation of the apparatus.

In operation, the apparatus of the invention performs in the following manner. At the start of a casting cycle, the end dam 21 is in position in the spigot end of the mold 5 as shown in FIGURE 1. The mold is rotated and molten metal is poured into it through the bell core at the opposite end of the mold. The end darn makes frictional contact with the end of the mold, and as a result, it rotates with the mold. The molten metal spreads out evenly along the length of the mold and is prevented from pouring out the spigot end of the mold by end dam 21 which provides an end wall which extends inwardly a distance at least equal to the thickness of the pipe. After the molten metal is solidified mold rotation is stopped.

At this time air cylinder 14 is actuated resulting in the movement of shaft 15 through sleeve 16, and lever 19 which carries the end dam 21 also moves away from the end of the mold thus disengaging the end dam from the mold. As shaft 15 moves through sleeve 16, pin 17 follows slot 18 to the position shown in FIGURE 2. The initial portion of the slot runs longitudinally, therefore, the lever 19 and end dam 21 move straight away from the end of the mold 5. However, as the pin 17 enters the portion of the slot 18 which follows a helical path, the shaft 15 turns in sleeve 16 thus rotating lever 19 clear of the end of the mold. The mold is then moved longitudinally against fixed push-out lance 12 and the cast pipe is extracted from the mold. After the pipe is extracted the mold is returned to its original position and air cylinder 14 is actuated in the reverse direction. As the pin 17 follows slot 18, the lever 19 rotates into a position adiacent the end of the mold, and the end dam is seated in the end of the mold as the shaft 15 continues its longitudinal movement. At this point the end dam is seated in casting position and the machine is ready to go through another cycle.

From the above, it is seen that the apparatus of this invention provides a rapid and simple means for moving an end dam into position for casting and then moving it free of the mold to permit extraction of the pipe cast. All that is required is the application of a longitudinal force, by a suitable means such as a pneumatic cylinder, on the end of the shaft on which the lever holding the end dam is mounted. The pneumatic cylinder may be actuated either manually or automatically by means of timers and limit switches, and in either case the additional burden placed on the machine operator is insignificant. In addition, the movement of the end dam is both smooth and rapid so that the machine may proceed extracting immediately upon solidification of the molten metal in the mold.

While present preferred embodiments of the invention have been described and the description has made reference to the structure of a casting machine with which the apparatus of the invention may be used, it is obvious that the invention is not limited to the embodiments shown and that the apparatus of the invention may be used with casting machine of various designs. Accordingly, it is to be distinctly understood that the invention is not to be so limited but includes all embodiments which come within the spirit and scope of the appended claims.

I claim:

1. A closure means for closing the spigot end of a cylindrical metal mold for casting tubular members comprising a sleeve mounted in fixed relation to the spigot end of the mold with its longitudinal axis parallel to the longitudinal axis of the mold, a shaft slidably mounted in said sleeve, guide pin and guide slot means provided along the adjacent surfaces of the sleeve and shaft for directing the movement of the shaft with respect to the sleeve, said guide slot having a substantially axially extending portion which guides the shaft longitudinally preventing rotation and a helical portion which causes the shaft to rotate as the guide pin follows the helical path, means for reciprocating the shaft back and forth longitudinally in the fixed sleeve, an arm attached to the shaft and positioned so that an end dam mounted at its free end is aligned with the end of the mold when said guide pin is in the longitudinal portion of the guide slot and is moved transversely with respect to the mold when the guide pin moves along the helical portion of said guide groove, said end dam being rotatably mounted on said arm.

2. A closure means for closing the spigot end of a cylindrical metal mold for casting tubular members comprising a sleeve mounted in fixed relation to the spigot end of the mold with its longitudinal axis parallel to the longitudinal axis of the mold, a shaft slidably mounted in the sleeve, a guide slot cut into one of the opposing surfaces of the shaft and sleeve, a guide pin protruding from the other opposing surface and extoending into the guide slot, said guide slot having a substantially axially extending portion which guides the shaft longitudinally preventing rotation and a helical portion which causes the shaft to rotate as the guide pin follows the helical path, a fluid operated piston means for reciprocating the shaft longitudinally in the fixed sleeve, an arm attached to the shaft and positioned so that an end dam mounted at its free end is aligned with the mold when said guide pin is in the said axial portion of the guide slot and is moved transversely with respect to the mold when the guide pin moves along the helical portion of said guide groove, said end dam being rotatably mounted on said arm.

3. A closure means for closing the spigot end of a cylindrical metal mold for casting tubular members comprising a sleeve mounted in fixed relation to the spigot end of the mold with its longitudinal axis parallel to the longitudinal axis of the mold, a shaft slidably mounted in the sleeve, a guide slot provided in said sleeve, a guide pin protruding from said shaft and extending into said guide slot, said guide slot having a substantially axially extending portion which guides the shaft longitudinally preventing rotation and a helical portion which causes the shaft to rotate as the guide pin follows the helical path, a fluid operated piston means for reciprocating the shaft longitudinally in the fixed sleeve, an arm attached to the shaft and positioned so that an end dam mounted at its free end is aligned with the mold when said guide pin is in the said axial portion of the guide slot and is moved transversely with respect to the mold when the guide pin moves along the helical portion of said guide groove, said end dam being rotatably mounted on said arm.

4. A closure means for closing the spigot end of a cylindrical metal mold for casting tubular members comprising a sleeve mounted in fixed relation to the spigot end of the mold with its longitudinal axis parallel to the longitudinal axis of the mold, a shaft slidably mounted in the sleeve, a guide slot provided in said shaft, a guide pin protruding from the inner surface of said sleeve and extending into said guide slot, said guide slot having a substantially axially extending portion which guides the shaft longitudinally preventing rotation and a helical portion which causes the shaft to rotate as the guide pin follows the helical path, a fluid operated piston means for reciprocating the shaft longitudinally in the fixed sleeve, an arm attached to the shaft and positioned so that an end dam mounted at its free end is aligned with the mold when said guide pin is in the said axial portion of the guide slot and is moved transversely with respect to the mold when the guide pin moves along the helical portion of said guide groove, said end dam being rotatably mounted on said arm.

References (Iited in the file of this patent UNITED STATES PATENTS 2,480,284 Boucher Aug. 30, 1949 2,613,410 Johnston Oct. 14, 1952 2,631,342 ROmine Mar. 17, 1953 2,686,933 Wood Aug. 24, 1954 2,729,865 Kaveny Jan. 10, 1956 2,849,769 Lasater Sept. 2, 1958 

